In spite of numerous predictions of a cashless society, the amount of cash in circulation has not declined. There are today an estimated 360 billion transactions in the EU every year to be compared with 60 billion non-cash transactions. The handling of cash is a very cost consuming operation still involving a lot of manual handling and transportation to and from consumers, retailers, banks, cash centres and National banks. The cash is counted on numerous occasions during this circulation and the security problems are extensive. The annual cost for handling of cash in the European Union is around 50 billion Euro.
Conventional banknote sorting and counting devices are designed for automatic processing of banknotes of any issue, value and country. The process on which the operation of the device is based consists of determining authenticity, denomination and decay level of a banknote using full images—obtained with scanning devices—of both banknote sides inter alia in the visible spectral range and in the infrared spectral range. The images are transmitted to and processed in a computing unit where obtained images are compared to reference images with the help of preinstalled pattern recognition software.
A number of different measures have been taken in order to secure banknotes against counterfeits, e.g. by printing pictures on banknotes with so-called metameric inks; these pictures cannot be seen with a naked eye and only reveal themselves in the infrared spectrum. Knowing a concrete infrared image, it is possible to develop a detector that checks several certain points on the banknote surface for availability or absence of metameric ink.
EP-1160737 relates to a method for determining the authenticity, the value and the decay level of banknotes, and a sorting and counting device.
WO-95/24691 relates to a method and apparatus for discriminating and counting documents that inter alia comprises a memory that stores master characteristic patterns corresponding to associated predetermined surfaces of a plurality of denomination s of genuine bills.
GB-2199173 relates to a bill discriminating device adapted to carry out an operation by extracting data from only a characteristic region of a bill.
The inventors to the present invention have identified a need of improved detection capabilities regarding banknotes being ink dyed as a result of robbery.